The sociological rule that one person wearing a fedora in a larger group may be stylistically unique, but two or more people wearing a fedora in a larger group renders every person in that group a douchebag.

Check it out - another fedora. What a douchebag.

No, wait - if it was just that one dude it might be cool, but two of his bros are wearing them too. According to the Fedora Douchebag Threshold Theorem, all five of them are douchebags.